1. Field of the Invention
The present invention relates to a liquid crystal display device and a method of fabricating the same, and more particularly to a liquid crystal display device having a color filter with a three-dimensional (3D) pattern structure provided with a transmissive pattern for selectively transmitting light of a specific wavelength, and a method of fabricating the same.
2. Discussion of the Related Art
Recently, as information displaying becomes more attractive and demands on the use of portable information media increase, research and commercialization of light and thin flat panel displays (FPDs), which substitute cathode ray tubes (CRTs) as the existing display devices, have increased. Among the FPDs, liquid crystal display (LCD) devices display images using optical anisotropic property of liquid crystal. The LCD devices exhibit excellent resolution, color rendering property, image quality and the like, so they are widely applied to laptop computers, desktop monitors, and the like.
The LCD device includes a color filter substrate, an array substrate, and a liquid crystal layer interposed between the color filter substrate and the array substrate. The fabrication of the LCD device requires performing a masking process (i.e., a photolithography process) multiple times. Accordingly, reducing the number of masks can enhance productivity.
Hereinafter, a structure of a related art LCD device will be described in detail with reference to FIG. 1. FIG. 1 is a perspective view showing a structure of the related art LCD device. As shown in FIG. 1, the LCD device includes a color filter substrate 5, an array substrate 10, and a liquid crystal layer 30 interposed between the color filter substrate 5 and the array substrate 10.
The color filter substrate 5 is provided with a color filter C having a plurality of sub color filters 7 for rendering red (R), green (G), and blue (B) colors, a black matrix 6 dividing adjacent sub color filters 7 and blocking light transmission through the liquid crystal layer 30, and a transparent common electrode 8 for applying a common voltage to the liquid crystal layer 30.
The array substrate 10 is provided with a plurality of gate lines 16 and data lines 17 arranged horizontally and longitudinally to define a plurality of pixel regions P, thin film transistors (TFTs) T as switching devices formed at intersections between the gate lines 16 and the data lines 17, and pixel electrodes 18 formed on the respective pixel regions P.
The color filter substrate 5 and the array substrate 10 facing each other are bonded to each other by a sealant (not shown) formed at an edge of an image display region, thereby constructing a liquid crystal panel. The attachment between the color filter substrate 5 and the array substrate 10 may be implemented by an alignment key (not shown) formed either at the color filter substrate 5 or at the array substrate 10.
In order to prevent light leakage due to an alignment error upon attachment, a line width of the black matrix is set to be wide to ensure an alignment margin. However, an increase in the line width of the black matrix results in a decrease of the aperture ratio of the liquid crystal panel.
The related art color filter used in LCD devices is configured to filter portions of the incident light by absorbing light with frequency components corresponding to unnecessary colors using dyes or pigments. In particular, the color filter transmits light with only one of the three primary colors (i.e., RGB) among the white light incident upon one sub-pixel. Accordingly, it is difficult to expect transmittance of more than 30% for the color filter. Therefore, the transmission efficiency of a panel is lowered, which causes power consumption due to the need for increasing the backlight power.
FIG. 2 is an exemplary view showing transmission efficiency of a panel upon the use of a related art color filter using a pigment dispersing method. As shown in FIG. 2, light emitted from the backlight is reduced to less than 5% of its original amount while transmitting sequentially through a polarizer, TFT array, liquid crystal, and color filter. In this example, the polarizer, TFT array, and color filter have transmittance of about 40%, 45-55%, and 25%, respectively.
In fabricating the related art color filter, color resist coating, exposure to light, development and hardening processes are repeated for each primary color. Accordingly, the whole fabrication process is complicated. Further, in addition to a TFT process line, a color filter process line should be run to fabricate the color filter on a color filter substrate, thereby increasing a line installation cost.